Leak preventing device



Oct. 25, 1,932., J. w. I'ATTER l 1,884,374

LEAK PREVENT'ING DEVICE Filed sept. 17, 1928 5 Sheets-Sheet 1 Oct. 25,lgz. I J, w, TA1-TER 1,884,374

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f. W MMM? Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE JOHN W.TATTER, OF CHICAGO, ILLINOIS, ASSIGNOR TO LEWIS DIFFERENTIAL COMPANY, OFCHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS LEAK PREVENTING DEVICEApplication ed September 17, 1928. Serial No. 306,599.

My invention relates t devices in the nature of packing devices forpreventing the leakage of fluid from valves and the cylinders of pumps,or the like, and to prevent the leakage of fluid past the pistons orvalves in pumps, cylinders, or the like.

My invention is particularly adapted to be embodied in hydraulic brakesystems of the kind described and claimed in my copending application,Serial No. 211,529, iiled August 8, 1927, a particular object of thepresent invention being to provide improved devices for preventing theescape of fluid from the systems.

Another object of the invention is to provide devices of the kinddescribed which will operate successfully over long periods of time andwill not disintegrate or deteriorate when the mechanism in which theyare embodied is subjected to much use. Y

Many other objects and advantages of the construction herein shown anddescribed will be obvious to those skilled in the art from thedisclosure herein given.

To this end my invention consists in the novel construction, arrangementand combination of parts herein shown and described, and moreparticularly pointed out in the claims.

In the' drawings, wherein like reference characters indicate like orcorresponding parts:

Fig. 1 is a plan vienv of the chassis ofan automobile upon which brakemechanism embodying the invention is mounted;

Fig. 2 is a section taken on line 2-2 of Fig. 3 is a view illustratingthe manner in which some ofthe mechanism shown in Fig. 2 is assembled;

Fig. 4 is a section taken on line 4-4 of Fig. 1;

Fig. 5 is a section taken on line Fig. 4;

Fig. 6 is a View illustrating the manner in which some of the mechanismshown in Fig. 4 is assembled;

Fig. 7 is an enlarged section taken on line 7 7 of Fig. 1;

Fig. 8 is an enlarged section taken on line 8-8 of Fig. 7;

Fig. 9 is a view illustrating the manner in which some of the mechanismshown in Fig. 8 is assembled;

Fig. 10 illustrated a modified form of the invention embodied inmechanism Which may be used in place of the mechanism illustrated inFig. 8;

Fig. 11 is a central longitudinal section through the improved sealingdevice shown in Fig. 10, the improved device being contracted in Fig.11;

Fig. 12 is a fragmentary section through brake mechanism adapted' to beemployed in place of the brake mechanism shown in Fig.

Fig. 13 is an enlarged section taken on line 13-13 of Fig. 12;

Fig. 14 is a central section taken through the improved sealing deviceshown in Fig. 13 to illustrate how the improved sealing device isexpanded when it is assembled With the remainder of the brake mechanism;

Fig. 15 is a section taken through brake mechanism adapted to beemployed in place or seal forming part of the mechanism showy!- in Fig.17; and

Fig. 19 is a section taken through brake mechanism which may be employedin place of the mechanism shown in Figs. 4 and 17.

Vhile I have disclosed my present inven-v tien in connection with brakemechanism, it is to be understood that the invention is limited to thisuse only to the extent indicated in the appended claims.

Referring for the present to Figs. 1 to 9,

vof the brake mechanism shown in Figs. 7, 8,

inclusive, wherein I have shown several forms of the invention embodiedin brake mechanism which is mounted upon a chassis 10, the brakemechanism is shown assembled in Fig. 1 to facilitate the task ofdisclosing this A invention. It will be noted that this mechanismresembles that shown in my copending application, Serial No. 211,529,filed August 8, 1927, and operates in substantially the same manner sothat a detailed description thereof need not be given in this instance.Briefly, it comprises brakes 16 and 17 provided for the front and rearwheels 18 and 19, respectively, of the chassis 10. The brakes are of thehydraulic or fluid operated type and are operatively connected throughpipes or tubing20 with a pipe line 21 preferably arranged transverselyof the chassis 10. A substantially vertically disposed pipe or tube 23operatively connects the pipe or tube 2l with a filling and regulatingdevice which is designated generally by the reference character 25.

Referring to Figs. 1 and 4, it will be noted that afoot or brake pedal27 is adapted to displace a piston 28 arranged in a chamber 29 which isformed in a cylinder 30, the chamber 29 being arranged to communicatewith the pipe 21 through ports 32 which are formed in a cap 33 closingone end of the chamber29.

Some details of the construction of the lling and regulating device 25differ from the corresponding details of construction of the filling andregulating device shown in my copending application, Serial No. 211,529so that they may more readily cooperate with and form parts of im rovedmeans for effectively sealing the filling and regulating device (seeFig. 2). It will be noted that the filling and regulating device 25comprises a receptacle 35 which communicates through a port 36 with achamber 37 that is formed in a cylinder 38 and a cap 39 the cap 39 beingarran ed to close one end o ,the cylinder 38. The c amber 37 alsocommunicates with the pipe 23 through a port 40 and the flow of duid orliquid through the ports 36 and 40 is controlled by valves 42 and 43,respectively. IThe stem of the valve 43 is provided with an outwardlyextending annular flange 44 which is slidably journaled in a cylindricalchamber 45, a spring 46 being positioned in the chamber 45 t0 yieldinglyhold the valve 43 in a position wherein it does not close the port 40.rlfhe chamber 45 is formed in a housing 50 in which the receptacle 35and the chamber 37 are also formed. One end of the chamber 45 is closedby a cap 48 which is secured in place by bolts 49, or the equivalent,and clamped between the cap 48 and the housing 50 is a member 51 whichis pref-` erably formed from rubber, or the like, but may be formed fromany suitable elastic material. The member 51 is preferably provided withan integral annular ange 52 positioned in an annular groove 53 formed inthe housing 50. The member 51 has a substantially central aperture 54which is bounded by an annular flange 56, the annular fla'nge 56 beingadapted to fit snugly around a boss 57 preferably formed integral withthe valve 43. It will be noted that the diameter of the chamber 45 isslightly larger than that of a chamber 58 formed in the cap 48 so thatthe cap forms a stop which limits the distance the valve 43 may bedisplaced to the left (F ig. 2) by the spring 46. The central portion ofthe member 51 is preferably clamped between the annular flange 44 and apiston member 60 which is slidably journaled in the chamber 58, thepiston member 60 being rigidly secured to the valve 43 by a screw 61, orthe equivalent. The construction is .preferably such that the member 51is Comit may be rotated' to displace the ball 66 and t also the pistonmember 60 and the valve 43 against the action of the spring 46.

As set forth in my above-mentioned copending application, the valve 43is alternately closed and opened during the process of producing apartial vacuum in the system before the oil or other fluid is introducedinto the system. After the system has been properly filled with anysuitable fluid, the pressure maintained in the system will tend to causethe fluid to escape from the system through the outer end of the chamber45. However, such leakage is prevented by the member 51 whichhermetically seals the outer end of the chamber. interfere with theoperation of the valve 43 as it is flexible and elastic.

Disposed within the chamber 37 is a fabricated piston which preferablycomprises complementary members 71 and 72 between which a portion of amember 73 is clamped, the member 73 being preferably formed from rubber,or the equivalent, (see Fig. 2). As shown, the member 7 3 is preferablysubstantially cup-shaped and preferably comprises a disc between 'themembers 7l and 72. flFhe 1.3

The member 5l does not inner surface of the disc 75 is preferablyprovided with an annular groove 77 arranged concentric with an aperture78 formed in the disc and the member 71 is preferably provided with anannular flange 79 adapted to en-` gage the annular groove 77. Thisconstruction tends to prevent distortion of the material disposed aroundthe aperture 78 and this aperture is preferably of a diameter `whichinsures that it will fit snugly around a. boss 80 preferably formedintegral with the member 71. An annular flange 82 is preferably formedintegral with the cylindrical wall 74 and is preferably clamped betweenthe housing and the cap 39, screws 83, or the equivalent, beingpreferably provided to rigidly secure the cap to the housing. At theouter margin of the annular flange 82, I preferably provide a. secondannular flange 84 adapted to rest in an annular groove 85 formed in thehousing 50.

The piston member 72 is preferably rigidly secured to the piston member71 by means comprising a collar 86 which is screwthreaded into thepiston member 71 and is provided with an annular flange or headi87adapted to lclamp the piston member 72 against the piston member 71, agasket 89 of any suitable material being preferably positioned betweenthe flange 87 and the piston member 7 2. Screw-threaded through thecollar 86 is a post 90 which is r0- tatably journaled in the cap 39 andis held against longitudinal displacement relative to the chamber 37 bya collar 91 and an annular flange 92, the annular flange 92 beingpreferably formed integral with the post 90. The outer end of the post90 is preferably provided with a handle member 94 whereby the post maybe rotated to displace the cylinder in the chamber 37.

In Fig. 3 I have shown an exploded7 view of the piston members 71 and 72and the member 73 to illustrate the appearance and the preferreddimensions of the member 73 when it is not distorted by the members 71and 72. In practice, I find it preferable to mold the member 73 so thatthe internal diameter of its cylindrical wall 74 is less than thediameter of the cylindrical surface of the member 71 and so that theexternal diameter of the disk portion is considerably less than thenormal external diameter of the cylindrical wall 74. Then when themember 73 is assembled with the members 71 and 72 and the disk portion75 is compressed, it will expand laterally until its external diameteris substantially equal to the internal diameter of the chamber 37. Thedisk portion 75 is preferably compressed about 40% of its normalthickness so that it is firmly clamped between the members 71 and 72 andis not readily displaced therefrom. Obviously, the member 73 forms aseal for the chamber 37 and prevents leakage from it.

' (Fig. 4).

Referring now to Figs. 4, 5 and 6, it will be noted that the chamber 29,in which the piston 28 is slidably journaled, is sealed by a cup-shapedmember 95 comprising a substantially cylindrical wall 96 with which thedisk portion 97 is preferably formed integral. The member 95 ispreferably formed of rubber or the equivalent. The disk portion 97 isprovided with an aperture 98 arranged to fit snugly around a boss 99which is preferably formed integral with a member 100 and themember 100is in reality an extension of the piston 28. As shown, the boss 99 seatsin a recess 102 formed in the piston 28 and the member 100 is secured tothe piston by a bolt 103. Interposed between the member 100 and one endof the chamber 29 is a compression spring 105 which tends to displacethe piston 28 to the right Obviously, when the piston 28 is displaced tothe left (Fig. 4) by means of the brake lever 27, fluid disposed in theleft hand end of the chamber 29 will be discharged therefrom through theports 32 into the pipe line. 21. However, when pressure is removed fromthe brake pedal 27, the spring 105 will displace the piston 28 to theright (Fig. 4) and restore the foot pedal 27 to its original position.

It will be noted that the external diameter of one end of the member 100is substantially equal to the internal diameter of that portion of thechamber 29 formed in the cap 33, this portion of the chamber 29 beingsmaller in diameter than that portion in which the piston 28 is slidablyjournaled. This construction provides an annular space 108 between themember 100 and the cylindrical surfaces of the larger portion of thechamber 29 and accommodates the cylindrical wall 96 of the member 95. Inthe preferred embodiment of the invention, the cylindrical wall 96 fitsloosely in.. the annular space 108 throughout the greater portion of itslength but it will be noted that the right hand end (Fig. 4) of themember 100 is provided with a head 109 which is of larger diameter thanthe normal internal diameter of the cylindrical wall 96 (see Fig. 6). Anannular groove 112 formed in the head 109 accommodates an annular flange113 preferably formed integral with the disk portion 97 and the diskportion 97 is preferably compressed between the piston 28 and the member100 to such an extent that it forms aseal to prevent leakage from thechamber 29. The flange 113 holds the disk portion 97 firmly in placebetween the piston 28 and the member 100. As best illustrated in Fig. 6,the normal external diameter of the cylindrical wall 96 is preferablyless than the diameter of the piston 28 when the member 95 is notassembled with the piston and its extension member 100. disk portion 97is clamped between the member 100 and the piston 28, it expandslaterally However, when the .l and prevents the member 100 from cuttingthrough the disk portion 97. The member 95 is preferably provided withan integral flange a adapted to be compressed between the cylinder 30and the cap 33l and formed integral with the flange 95a is a flange 955which engages an vannular shoulder 33a formed on the cap 33. The flange9522 prevents the flange 95erl from being pulled out from between thecap and cylinder.

Referring now to Figs. 7 to 9, inclusive, wherein I have illustrated thedetails of one of the rear brakes 17, the reference character designatesthe brake drum and the reference character 121 designates the brakeband.

The brake band is provided with a lining 122 engageable with theinternal cylindrical surface of the brake drum 120. Means for expandingthe brake band 121 comprises a piston 123 which is slidably ournaled ina cham ber 124 formed in a cylinder 125, the cylinder 125 being closedat one end by a cap 126 which is provided with a port 127. The port 127also communicates with one of the pipes or tubes 20 so that fluid willbe forced into the chamber 124 when the brake pedal 27 is depressed.

The piston 123 comprises members 127 and 128 which are secured to eachother by a bolt 129. As shown, the member 128 is provided with asubstantially cylindrical boss 130 y which projects into a recess 131formed in the member 127, the boss 130 being arranged to abut againstthe bottom surface of the recess 131. Clam'ped between the members 127and 128 is a cup-shaped member 132 which is preferably formed of rubber,or the equivalent, and preferably comprises a thin cylindrical wall 133formed integral with the disk portion 134 which forms the bottom ofthecup-shaped member 132. An inwardly projecting annular flange 136 formedintegral with the disk portion 134 projects into an annular groove 137formed in the member 128. The construction is preferably such that whenthe boss 13() abuts the bottom surface of the recess 131, the diskportion 134 is compressed and is rmly held in place between the members127 and 128. As shown in the exploded view (Fig. 9) the externaldiameter of the cylindrical wall 133 is less than the diameter of thechamber 124 when the member 132 has not been assembled with the members127 and 128. However, when the disk portion 134 is compressed betweenthe members 127 and 128 it expands laterally until it becomes of adiameter substantially equal to the diameter of the chamber 124. At theend opposite the disk portion 134, the cylindrical wall 133 is providedwith an outwardly projecting annular flange 139 which is, in turn,provided with an annular flange 140 adapted to seat in a groove 141provided in the cap 126. The annular flange 139 is compressed betweenthe cap 126 and the cylinder 125m such manner that it effectively sealsthe joint between the cap and the cylinder. The annular flange 140prevents the flange 139 from being pulled out of the space between thecap and the cylinder.

Projecting inwardly from the ends of the brake band 121 are bracketmembers 142 and 143 which engage slots 144 and 145, respectively,provided in the cap 126 and the member 127, respectively. Obviously,when fluid under pressure is introduced into the left hand end (Fig. 8)of the chamber 124 through the port 127, the piston 123 will bedisplaced to the right (Fig. 8) and will expand the band 121. Also asexplained in my copending application, Serial No. 211,529, filed August8, 1927 the cap and cylinder can move to the left (Fig. 8) and displacethe bracket 142 together with that end of the band to which it issecured.

To prevent dust, dirt, or the like, from enhand (Fig. 8) end thereof, Ipreferably provide a flexible sleeve which has one end clamped to thecylinder 125 and has its other end clamped to an annular flange 152provided upon the outer end of the member 127. The flexible sleeve 150is preferably provided with an inwardly extending annular flange 153engageable with an annular groove 155 formed in the flange 152.Intermediate. its ends, the flexible sleeve 150 is provided with aplurality of annular folds 157 so that the sleeve may elongate orcontract with the movement of tlie piston 123. The sleeve 150 maybe'made of leather but is preferably made of rubber, or the equivalent.

In Figs. 10 and 11 I have shown a modified form of the apparatus shownin Figs. 8 and 9. Thus, I provide a cylinder 160 in which a piston 161is slidably journaled, the piston being formed from a substantiallycylindrical member 162 which is rigidly secured to a member 163 by meanscomprisinga tube 164 preferably formed integral with a bracket member165. A port 166 formed in the bracket member and the tube 164 providesmeans whereby fluid may be forced into the cylinder 160 from one of thepipes or tubes 20 shown in Fig. 1, it bein@F readily understood that themechanism s own in Figs. 10 and 11 can be used in place of the mechanismshown in Figs. 8 and 9. Slots 170 and 171 provided in the bracket member165 and the cylinder 160, respectively, are adapted to cooperate withbracket members similar to the bracket members 142 and 143 shown in Fig.7.

The member 163 is screw-threaded upon the tube 164 and it is providedwith a. chamber 172 into which fluid may be introduced by way of theport 166 and it will be noted that the chamber 172 communicates with the'tering the cylinder 124 through the right exterior surface of themember 163 throu h a port 174 so that fluid introduced into t e chamber172 by way of the port 166 will exert pressure againstI a member 175which is preferably carried by the member 163 and is preferably formedfrom rubber, or the equivalent. In this embodiment of the invention, themember 175 comprises a relatively thin wall 177 enclosing a chamber 178into which the member 163 may be forced through an aperture 179 formedin a disk portion 180 the disk portion 180 being preferably formedintegral with the thin wall 177. The disk portion 180 is preferablyprovided with an inwardly extending annular flange 181 adapted to engagea. groove '183 formed in the member 163. The end portion 180 isrelatively thick and when the member 175 is assembled with the members162 and 163, it is compressed so that it forms a seal between thesemembers. The amount the disk portion 180 can be compressed is limited bya boss 185 which is formed upon the member 162 and projects into arecess 186 ,formed in the member 163. The internal diameter of themember 175 is normally less than the external diameter of the member 163so that it is expanded when the member 163 is forced into it. This isshown by dotted lines in Fig. 11. lVhen the apparatus shown in Fig. 10is operated, fluid is forced into the chamber 172 by way of the port 166and it passes through the port 174 to displace the c linder 160 to theright (Fig. 10) and to disp ace the piston 161 to the left (Fig. 10),the member 175 being elongated. As the disk portion 180 seals the jointbetween the members 162 and 163, fluid urged through the port 174 willbe retained lwithin the member 175 and will not escape or leak from thecylinder 160.

In Figs. 12,13 and 14. I have shown another form of the inventionembodied in apparatus which'cau also be used in place of the a paratusshown in Figs. 7, 8 and 9. Thus, I ave shown a. bracket comprising abrake drum 195 which cooperates with a brake band 196 having a brakelining 197. Interposed between the ends of the brake band 196 is meansfor.

expanding the brake comprising a bracket member 198 and a cylinder 199.the cylinder 199 being rigidly secured to the bracket member. A port 200formed in the bracket member 198 is adapted to communicate with a pipe202 which is the equivalent of one of the pipes 20 shown in Fig. 1 sothat fluid may be forced into the cylinder. Slidably journaled in thecylinder 199 is a piston 203 to which a rod 204 is rigidly secured, theouter end of the rod being adapted to engage a slot 205 formedl in abracket member 206 which is rigidly secured to one end of the brake band196.k Secured to the other end of the brake band 196 is a bracket member207 provided with a. slot 208 which is engaged by a lug 209 preferablyformed integral with the bracket member 198. Interpesed between thepiston 203 and a substantially cylindrical lu 210 formed integral withthe bracket mem er 198 is a cupshaped member 211 which is preferablyformed from rubber, or the equivalent. The clip-shaped member 211 ispreferably provi ed with a substantially cylindrical wall 213 and formedintegral with the wall 213 is an imperfo'rate disk portion 214 againstwhich fluid may be forced through the port 200. It will be noted thatthe disk portion 214 is relatively thick as compared with 'thecylindrical wall 213 and that the cylindrical wall 213 is provided withan integral' outwardly projecting annular flange 215 which, at its outerend, is provided with an annular flan e 216, the annular flange 216being arranged 1n a groove 217 forlned in the bracket member 198. Theannular flange 215 is clamped securely between the bracket member 198and the cylinder 199, the flange 215 being compressed so that it forms aseal in the joint between the bracket member 198 and the cylinder 199.

The wall 213 is preferabl tapered as shown in Fig. 14 when the cup-siaped member 211 is not assembled with the boss 210 but the constructionof the cup-shaped member 211 is such that when it is forced upon theboss 210` the disk portion 214 is expanded laterally so that itsdiameter is substantially equal to the diameter of the chamber withinthe cylinder 199. When fluid under sufficient pressure is introducedinto the port 200, it displaces the disk portion 214 to the right (Fig.13) and elongates the wall 213. This displacement of the disk portion214 causes like displacement of the piston 203 and it, in turn,displaces the bracket member 206 to expand the brake band 196. Thebracket member 198 is arranged between the ends of the brake band 196and is relatively free to move toward the left (Fig. 13) so that whenfluid under sufficient pressure is introduced into the port 200, bothends of the brake band are dis laced in directions away from each other.t will be noted that the cup-shaped member 211 effectively seals theinner end of the ort 200 so that fluid can not escape or leak rom thecylinder 199.

T o prevent. dust, dirt, or the like, from entering the cylinder 199through the right hand (Fig. 13) end thereof, I preferably provide aflexible sleeve 220 of rubber, or the equivalent. which has one of itsends clamped to the rod 204 and has the other of its ends clampedbetween one end of the cylinder 199 and a collar 222 which isscrew-threaded upon the cylinder.

In Fig. 15 I have shown a modified form of the apparatus shown in Fig.13, in which modified apparatus, a cup-shaped member 230 formed ofrubber, or the equivalent, and substantially identical with theaforementioned Cup-shaped member 211 is employed. The

apparatus shown in Fig. 15 comprises a bracket member 231 and a cylinder232 which have the same functions as the bracket memshaped member 230.Slidably journaled in the cylinder 232 is ar piston 235 provided with aslot 236 engageable by a bracket member 237 which may be rigidly securedto one end of a brake band and corresponds to the bracket member 206shown in Fig. 12. A slot 239 formed in the bracket member 231 is engagedby a bracket member 240 which corresponds to the bracket member 207 ofFig. 12. Obviously, when fluid under sullicient pressure is introducedinto the port 233, the disk portion 234 willbe displaced to the right(Fig. 15) so that there will be relative movement between the bracketmember 231 and the piston 235 to expand the brake band to which thebracket members 240 and 237 are attached.

Referring now to Fig. 16 wherein I have shown apparatus adapted to beemployed in place of the apparatus shown in Fig. 8, the referencecharacter 242 identifies a bracket member and the reference character243 identifies a cylinder which is rigidly secured to the bracketmember. The bracket member 242 and the cylinder 243 perform substantiially the same functions as the aforementioned bracket 198 and cylinder199, respectively, and the cylinder 243 slidably journals a piston 244which abuts against a conical wall 245 forming part of a cup-shapedmember 246 which is preferably formed from some elastic material such asrubber, or theN equivalent. The cup-shaped member 246 also comprises asubstantiallyA cylindrical wall 247 which is provided with an outwardlyextending integral flange 248 and at its outer margin, the flange 248 isprovided with an annular flange 249 adapted to engage an annular groove250 formed in the bracket member 242. Projecting into the cup-shapedmember 246 and fitting snugly therein is a boss 252 which is preferablyformed integral with the bracket member 242. A port 253 formed in thebracket member 242 and the boss 252 communicates with a pipe 255 whichmay be connected to the pipe 21 shown in Fig. 1. Engaging slots 256 and257 provided in the bracket member 242 and the piston 244, respectively,are bracket members 258 and 259, respectively, which have the samefunctions as the aforementioned bracket members 142 and 143 shown inFig. 8.

It will be noted that the boss 252 is provided with a conical end wall260 which abuts against the inner side of the conical wall 245 and itwill also be noted that the disk 244 has aconical depression 262 intowhich the cocnical wall 245 projects. The flange comprising a brakepedal 296 is y for displacing the pistonI 270 to the left (Fig.

248 is clamped between the bracket member 242 and the cylinder 243 andis compressed sufliciently to form a liquid tight seal at this point.The annular flange 250 prevents the flange 248 from being diawn frombetween the bracket member 242 and the cylinder 243 when the cylindricalwall 247 is tensioned.

When Huid under suiicient pressure is introduced into the port 253 itexerts pressure against the inner side of the conical wall 245 anddisplaces this wall, the cylindrical wall 247 being elongated. Suchdisplacement of the conical wall 245 causes relative displacementbetween the bracket member 242 and the piston 244 so that thevends ofthe brake band (not shown) to which the bracket members 258 and 259 areattached move away from each other to cause the brake band (not shown)to expand. Obviously, the cupshaped member 246 constitutes means toprevent leakage of fluid from the cylinder 243. In Figs. 17 and 18 Ihave shown apparatus adapted to be used in place of the apparatus shownin Fig. 4. A two-part piston 270 is shown' comprising members 271 and272 which are rigidly secured to each other by a bolt 27 3f Acylindrical boss 274 preferably formed integral with the member 271seats in a recess 275 formed in the member 272, the outer end of theboss being adapted to abut against the bottom of the recess 275. Thebolt 273 passes through an aperture 278 formed in the boss 274 and isscrew-threaded into the member 272. The member 272 is slidably journaledin a chamber or bore 279 formed in a housing member 280 and the member271 is slidably journaled in a chamber or bore 291 formed in at cap 292which closes one end of the chamber or bore 279. It will be noted thatthe members 271 and 272 are round in cross section and are coaxiallydisposed. Interposed between the member 271 and one end-of the chamberor bore 291 is a compression spring 294 which urges the piston 270 tothe right (Fig. 16). Means provided 16) against the action of the spring294. A port 299 formed in the cap member 292 communicates with atransversely extending bore 300. The transverse bore 300 provides meanswhereby the bore 299 may communicate with pipes (not shown) which arethe equivalent of the pipes 21 shown in Fig. 1. Clamped between themembers 271 and 272 is a bottom or end wall 303 of a cup-shaped member304 which also comprises a substantially cylindrical wall 305, thecylindrical wall 305 terminating at one end in an annular flange 306which, at its outer end is provided with an annular flange 307engageable with a groove 308 formed in the cap member 292. Thecup-shaped member 304 is preferably made from rubber, or the equivalent,and it will be noted that its cylindrical wall 304 is relatively thin ascompared with the thickness of the end or bottom wall 303. The end orbottom wall 303 is provided with a central aperture 310 which litssnugly around the boss 274 and bounding the aperture 310 is an annularflange 311 which' is preferably formed integral with the wall 303 andpreferably projects into an annular groove 312 formed in the member 271.On the outer side of the bottom or end wall 303 is a frustoconicalmember 315 preferably formed integral with the wall 303 and snuglyfitted in a frustro-conical recess 317 formed in the member 272. Inother words, the recess 317 is undercut and the member 315 is fittedinto it in such manner that it is not removable therefrom and can onlybe removed therefrom when the member 271 has been withdrawn from thecup-shaped member 304. The member 315 is inserted in the recess 317 bytemporarily deforming or depressing it and working it into the recessbefore the member 271 is assembled with the member 272. The marginalportion of the end wall 303 is compressed between the members 271 and272 to form a liquid tight seal between and the annular flange 306 iscompressed be- Itween the housing 280 and the cap member 292 to form aliquid tight seal at this point.

Obviously, when the brake lever or pedal 296 is displaced in a counterclockwise direction (Fig. 16) against the action of the spring 294 fluiddisposed in the chamber or bore 291 will be discharged from the bore orchamber 291 through the bores 299 and 300 to the brakes w-ith whichthese bores communicate. Then when the brake pedal is permitted toreturn to its original position, the fluid is forced back into the boreor chamber 291 and displaces the piston 270 to the right (Fig. 16) andelongat'es the cylindrical wall 304.

When the cup-shaped member 304 is nbt assembled with the members 271 and27 2 its external diameter is less than the diameter of the bore orchamber 279 so that both the cylindrical wall 304 and the end wall 303are expanded to the diameter of the bore or chamber 279 when the member304 is assembled with the members 271.and 272, the end wall 303 beingcompressed longiutdinally of the member 304 but being expanded laterallythereof. Of course, the marginal portion of the member 303 is compressedmore than the central portion thereof.

- Referring now to Figf19 wherein I have shown still another form ofappara-tus which may be employed in place of the apparatus shown in Fig.4, the reference character 320 designates a housing having a bore orchamber 321 which is closed at one end by a cap member 322 having a boreor chamber 323, the bore or chamber being coaxially disposed withrespect to the bore or chamber 321. Disposed in the bores or chambers321 and 323 is a two-part piston 325 which comprises members 326 and327, the members 326 and 327 being secured to each other by a bolt 328which projects through an aperture 329 formed in a cylindrical boss 330preferably formed integral with the member 326. The bolt isscrew-threaded into a member 327 and it will be noted that a recess 330is provided in the member 327 which recess accommodates the boss 320,the boss being adapted to abut against the bottom surface of the recess.bore or chamber 323 and the member 326 is a compression spring 332 whichyieldingly urges the piston 325 to the right (Fig. 18). Means comprisinga foot pedal 334-is provided for displacing the piston 325 to the left(Fig. 1S) against the action of the spring 332. A transverse bore 337provided in the cap member 322 provides means whereby a bore 336 maycommunicate with pipes (not shown) which are the equivalent of the pipes21 shown in Fig. 1, the bore 336 being in communication with the chamber323. Clamped between the members 326 and 327 is a bottom or end wall 339of a cup-shaped member 340 which also comprises a. substantiallycylindrical wall 341 formed integral with the end or bottom wall 339.The member 340 is preferably formed from rubber, or the equivalent. Thecylindrical wall 341 is provided with an outwardly extending annularflange 322 which is compressed and clamped between the cap member 322and the housing member 320. An annular flange 343 formed at the outeredge of the annular flange` 342 engages an annular groove 344 formed inthe cap member 322. It will be noted that the bottom or end wall 339 isrelatively thin Where it joins the cylindrical wall 341 and that itincreases in width toward its center until it is cut away at 350 and 351to engage the boss 340 and a boss 352, respectively, the boss 352 beingformed upon the member 327. An annular flange 355 forming part of theend wall 339 is relatively thin in comparison with the remainder of theend wall and is clamped between the boss 352 and a shoulder 357 formedupon the boss 330. It will be noted, however, that the greater portionof the end wall is thicker than the cylindrical wall 341 and that thetapered portion of the end wall 339 fits snugly and Ais compressed in anundercut annular groove 360 formed partly in the member 326 and partlyin the member 327. Obviously.l the wall 339 cannot be withdrawn from itsposition in the groove 360 unless the member 326 is withdrawn from themember 340. Therefore. when the wall 341 is tensioned there is nolateral displacement of the end wall 339.

When the brake pedal 334 is displaced in a counter clockwise direction(Fig. 18) against the action ofthe spring 332, fluid disposed in thebore or chamber 323 will be discharged throughthe bores 336 and 337 tothe pipes Interposed between one end of thev which are not shown whichare the equivalent of the pipes 21 in Figs. 1 and 4. Then when the brakepedal 334 is permitted to return to its original position, the fluidwill return to the bore or chamber 323 and with the assistance of thespring 322 will displace the piston 325 tothe right (Fig. 18). rl`hiswill tension or elongate the cylindrical wall 341.

Before the cup-shaped member 3l() is assembled with the members 326 and327 its external diameter is considerably less than the diameter of thebore or chamber 321. However, when the end wall 339 is compressedbetween the members 326 and 327, the end wall expands laterally until itassumes the diameter of the bor-ey or chamber 321 and the cylindricalwall 341 is expanded, of course, over the member 326. l

Having thus described my invention, it is obvious that variousimmaterial modifications may be made in the same without departing Vfromthe spirit of my invention; hence I do not. wish to be understood aslimiting myself to the exact form, construction, arrangement andcombination of parts herein shown and described, or uses mentioned.

lVhat I claimas new and desire to secure by Letters Patent is:

1. In a connection between a cylindrical chamber and a member 'operabletherein,

packing means therefor comprising a cupshaped rubber packing memberadapted to be clamped'to the wall of the chamber and having acylindrical side wall of relatively thin wall section whereby saidcylindrical side wall may be readily stretched axially thereof, saidcup-shaped member having a bottom wall integral with said side wall,said bottom signed my name.

JQHN W. TATTER.

packing'means therefor comprising ai cupshaped rubber packing memberadapted to be clamped to the wall of the chamber and havinga cylindricalside wall of relatively thin wall section whereby said cylindrical sidewall may be readily stretched axially thereof, said cup shaped memberhaving a bottom wall integral with said side wall, said bottom wallextending transversely of the axis of said cylindrical side wall, saidbottom wall having a relatively thick .wall section whereby to resistdeflection' outwardly there of when subjected to relatively high fluidpressure within said vcup-shaped packing member.

2. In a connection'between a cylindrical chamber and a member operabletherein, packing means therefor comprising a cupshaped rubber packingmember adapted to be clampedy to the wall of the chamber and having acylindrical side wall of relatively thin wall section whereby saidcylindrical side wall may be readily stretched axially thereof, saidcup-shaped member having a bottom wall integral with said 'side wall,said bottom wall extending transversely of the axis of said cylindricalside wall, said bottom wall having a relatively thick wall sectionwhereby to resist deflection outwardly thereof when subjected torelatively high fluid pressure within said cup-shaped packing member,said bottom wall section being Aat least twice` as thick as said sidewall section.

3. In a connection between a cylindrical chamber and a member operabletherein,

In testimony whereof, I have hereunto..l

